Recent progress in Ga₂O₃power devices

Abstract

This is a review article on the current status and future prospects of the research and development on gallium oxide (Ga 2 O 3 ) power devices. Ga 2 O 3 possesses excellent material properties, in particular for power device applications. It is also attractive from an industrial viewpoint since large-size, high-quality wafers can be manufactured from a single-crystal bulk synthesized by melt-growth methods. These two features have drawn much attention to Ga 2 O 3 as a new wide bandgap semiconductor following SiC and GaN. In this review, we describe the recent progress in the research and development on fundamental technologies of Ga 2 O 3 devices, covering single-crystal bulk and wafer production, homoepitaxial thin film growth by molecular beam epitaxy and halide vapor phase epitaxy, as well as device processing and characterization of metal-semiconductor field-effect transistors, metal-oxide-semiconductor field-effect transistors and Schottky barrier diodes.

Ultrawide‐Bandgap Semiconductors: Research Opportunities and Challenges

“…These wafers are fabricated from bulk single crystals synthesized by a variety of melt-growth techniques such as float-zone, [120,123] Czochralski, [124,125] vertical Bridgman, [126] and edge-defined film-fed growth (EFG) methods. [127][128][129] To date, EFG has an advantage over the other melt-growth methods in producing such wafers. Figure 6 displays a photograph of a 4-inch-diameter single-crystal Ga 2 O 3 wafer produced from an EFG-grown bulk crystal.…”

Perspective—Opportunities and Future Directions for Ga2O3

“…For p-type doping, there have been no reports on achieving conductive material with acceptors, 10 due to their predicted large ionization energies, presence of common n-type impurities and native defects and the resulting n-type background conductivity that must be overcome. This will require a systematic measurement of the ionization energies of candidate acceptors (by optical methods initially) and a better understanding of the compensation by native point defects and their complexes plays an important role in influencing the efficiency of doping in Ga 2 O 3 and related alloys.…”

“…However, the lower thermal conductivity of Ga 2 O 3 relative to other wide bandgap materials means these techniques must be even more Contacts on n-Ga 2 O 3 .-The usual approaches involve surface etching or cleaning to reduce barrier height or increase of carrier concentration of the surface through preferential loss of oxygen. 10,12,[23][24][25] To date, contact schemes involving IZO or dry etching in BCl 3 /Ar to enhance the surface n-type conductivity, followed by Ti/Au annealed at 500…”

Ordinary dielectric function of corundumlike α−Ga2O3 from 40 meV to 20 eV

“…The wide-band-gap semiconductor gallium oxide has a multitude of potential applications in spintronics [1], sensorics [2], solar-blind detectors [3], and transparent electronics [4,5]. It has long been known that Ga 2 O 3 crystallizes in several different polytypes [6], each with distinct physical properties.…”